CVE-2025-49894 is a security vulnerability classified as CWE-79, which relates to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This specific vulnerability affects the WP Emmet plugin developed by rewish, versions up to and including 0.3.4. The vulnerability allows for Stored XSS attacks, where malicious input is permanently stored on the target server (e.g., in a database) and later rendered in web pages without proper sanitization or encoding. This can enable attackers to execute arbitrary JavaScript code in the context of users visiting the affected web pages. The CVSS v3.1 base score is 5.9, indicating a medium severity level. The vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L) shows that the attack can be performed remotely over the network (AV:N) with low attack complexity (AC:L), but requires high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is low to low-medium, as the attacker can partially compromise these aspects through script execution. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in June 2025 and published in August 2025. Stored XSS in a WordPress plugin is particularly concerning because WordPress is widely used for websites, and plugins often have elevated privileges to modify site content and behavior. Exploiting this vulnerability could allow attackers to steal session cookies, perform actions on behalf of authenticated users, or deliver further malware payloads.

For European organizations using WordPress websites with the WP Emmet plugin, this vulnerability poses a risk of client-side compromise through stored XSS. Attackers could hijack user sessions, deface websites, or inject malicious scripts that lead to data theft or further exploitation. This is especially impactful for organizations handling sensitive user data or providing critical services online, such as e-commerce, government portals, or financial institutions. The requirement for high privileges and user interaction somewhat limits the attack surface but does not eliminate risk, as insiders or compromised accounts could be leveraged. The changed scope indicates that the vulnerability could affect other components or users beyond the immediate plugin context, potentially leading to broader compromise. Given the widespread use of WordPress in Europe and the importance of maintaining trust and data protection under regulations like GDPR, exploitation could lead to reputational damage, regulatory penalties, and operational disruptions.

1. Immediate mitigation should include auditing all WordPress installations for the presence of the WP Emmet plugin and its version. 2. Disable or remove the WP Emmet plugin until a security patch is released. 3. Implement Web Application Firewall (WAF) rules that detect and block typical XSS payloads targeting the affected plugin endpoints. 4. Enforce strict Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected websites. 5. Conduct thorough input validation and output encoding on all user-supplied data in custom code or other plugins to reduce the risk of XSS. 6. Monitor logs for suspicious activity indicative of attempted XSS exploitation, especially from users with elevated privileges. 7. Educate privileged users about the risks of interacting with untrusted content or links that could trigger stored XSS payloads. 8. Once available, promptly apply official patches or updates from the vendor. 9. Consider deploying security plugins that provide additional XSS protection and scanning capabilities. These steps go beyond generic advice by focusing on immediate plugin management, layered defenses, and user awareness tailored to the nature of this stored XSS vulnerability.